That's according to a new study by University of Pittsburgh researchers including Xianchen Liu, MD, PhD.
They studied 1,362 adolescents at five high schools in China. The students were about 14 years old, on average; most of them (60%) were boys.
About 20% of the students admitted ever smoking, but only about 4% were current smokers. Overall, nearly 22% said they had experimented with alcohol, and 16% were current drinkers.
Smoking and drinking were more common in older students. Compared with girls, boys were more likely to say they had smoked or drunk.
Liu's team analyzed the data, which included background information on the students' families.
Teen Sleep Study
After considering various factors, the researchers found that students who slept less than eight hours per night were more likely to smoke and drink.
Drinkers were also particularly likely to report having frequent nightmares and difficulty falling asleep. Smokers tended to go to bed after midnight, use sedatives, and have trouble falling and staying asleep.
The study doesn't prove which came first -- troubled sleep, smoking, or drinking. A long-term study is needed, but meanwhile, Liu's team says that helping teens get better sleep may help prevent adolescent substance use.
U.S. Teens and Sleep
Liu's study focused on teens in China. Curious about the sleep habits of U.S. teens? The National Sleep Foundation's "2006 Sleep in America Poll" included some 1,600 U.S. teens.
The poll showed that only one in five adolescents get the optimal amount of sleep for their age group (nine or more hours per night), and nearly half (45%) got less than eight hours of nightly sleep.
Poor sleep can make it harder to concentrate at school. Drowsy driving is another danger. In the National Sleep Foundation's poll, 5% of 512 teen drivers said they had nodded off or fallen asleep while driving in the previous year.
Here are tips for good sleep at any age:
- Stick to a sleep schedule. Go to bed and get up at the same time every day.
- Avoid caffeine and nicotine.
- Avoid alcoholic drinks and a large meal before bedtime.
- Relax before bedtime.
- Create a good sleeping environment. Keep your bedroom cool and quiet.
- See a doctor if you consistently have trouble sleeping.